But one finish line image stood out from the rest of the filth — ear-to-ear smiles through mud-encrusted faces.

"(Even with) all the mud, all the obstacles, all the running, we had a blast doing it," Dave Heino said, who ran with his daughter Natalie for the second-straight year.

And they don't plan on stopping coming to the race at Ron Cook's St. Clair farm. As a matter of fact, hardly anyone who finishes the race decided to not come back for more.

When St. Clair alumni and former cross country teammates John Cook and Kurt Brinker dreamed up the course five years ago, they wanted it to suit everyone from intense runners to the occasional thrill-seekers.

"This might have been the first time they ran or done any physical activity all year," John Cook said. "This course accommodates everybody."

The most treacherous part of the course comes in the final quarter mile. Three mud pools, two swampy hills with slick rope and countless ways to slip and fall greet all the runners at the end.

At the end of the race, Chicago's Andy Wyeth was thankful to put it behind him.

"It was relief just to be done," he said in his red, brown and blue American flag shirt. "But I'm going to do a lot more of these in my life."

There were only 400 participants when the first SwampFoot took place a half decade ago, but now that word has gotten out, the annual event is on a lot of people's to-do list.

"They keep coming back, and they keep bringing people with them," Ron Cook said. "The very first swamp foot, the runners went off at 9 a.m., and by 11 a.m. there wasn't a soul here."

Now the mud run, which boasts more than 60 obstacles, has heats running from 9 a.m. to 4:30 p.m. With thousands of runners coming to the family farm every year, it could be an easy way to make revenue, but that's just not the case.

Ron Cook said that every penny has either gone back into enhancing the course or toward Lone Survivor Foundation — benefiting former U.S Armed Forces member — and Liberty Riders, a therapeutic horse riding program.

"John and Kurt have not taken a dime off of this race yet," Ron Cook said. "They work on it all year long … It's a lot of work, and they do a phenomenal job with it.

"Everybody out here will say they have a great time."

Contact Matt Sheehan at (810)-989-6267 or msheehan@gannett.com. He's on Twitter at @MattSheehan333.